Minerals are grouped into two categories. Those that are considered to be required in our diets in amounts greater than 100 milligrams per day are called major minerals (calcium, chlorine, magnesium, potassium, phosphorus, sodium and sulphur). Those considered to be required in our diets in minute amounts (less than 100 milligrams/day) are called trace minerals. Each makes up less than 1/100th of one percent of our body weight. But that small amount is essential! But why do we need mineral supplementation?